Aluminum subframing is commonly used during construction of tensioned fabric structures. The aluminum substructures are composed of curved bearing arches made of high quality aluminum with [multilayered] fabric membrane placed between them. These load bearing arches are attached to the concrete foundation with lower flanges.
The outer and inner fabric membranes are comprised of individual panels which are fitted into corresponding slots in the adjacent aluminum substructure elements. An insulating package between outer and inner membranes may be installed which enhances structure's performance under most severe weather conditions.
Tensile fabric structures basic profile geometry consist of upright walls topped with double sided sloped roof. (gabled roof) Aluminum framework has radial curved design and smooth flowing outlines: so that structure's erect walls gently transition into pitched roof slopes. Such seamless transition between the vertical walls and the roof sides help to enhance an aerodynamic qualities of the building while eliminating stress points which are common with a traditional framework. The pitch of the roof slopes when combined with use of friction reducing fabric result in vastly reduced snow loads on structures by promoting snow's self removal due to the effects of gravity. For the buildings that are frequently exposed to the high winds we design structures with end walls having the same profile as the cross-section profile of the structure.
Aluminum subframe elements for tensile structures are extruded from AD31 alloy followed by quenching and artificial aging. This alloy belongs to a group of so called Avial alloys which is widely used in the aircraft industry. Unlike steel and wood, aluminum performs extremely well in humid environmental conditions while resisting harmful effects of UV radiation and acid rains. Aluminum is environmentally friendly - it emits no harmful substances or odours. It is also lightweight: AD31T1 alloy has 60% of the strength of Steel 3 while the density of aluminum is only 35% of that of Steel 3. In practice this means that parts made from Aluminum are about 1/3 the weight of steel while having the same strength. Even better, aluminum has indefinite life expectancy.
Tension membrane structure is made of technical fabric with polymer coating. We offer several options of fabrics with different qualities to choose from.
1. Tent fabric An outer membrane is comprised of high-quality polyamide fabric with Polyvinyl chloride (PVC) coating. Polymar 8205 fabric manufactured by Mehler Technologies of Germany retain high strength characteristics within wide temperature ranges: from -30 C to +70 C, has excellent chemical resistance and environmentally safe. Outer layer's friction reducing coating combined with the roof's pitch provide for snow's self removal under its own weight. Polymar fabric is well suited for display of logos and letterings. Different colors are available.
2. Architectural fabric. An outer membrane of architectural fabric with PVC coating and PVDF layer (Polyvinyldifluoride). Valmax architectural fabric with PVDF has all the necessary qualities of a tent fabric. It has exceptional fire-retardant capability and is expected to last longer due to the PVDF layer on top of PVC coating. This coating also provides protection from the sun's harmful UV rays and has antimicrobial/antifungal properties.
3. Architectural friction reducing fabric. Fabric with Polytetrafluoroethylene (PTFE) coating is known as Teflon fabric. We recommend to employ this fabric with structures that are exposed to heavy snow loads to facilitate snow self removal from the structure's roof.
Following options of tensile fabric structures are available:
- subframe with single outer membrane;
- subframe with double layered (inner and outer) membranes;
- subframe with double layered membrane with thermal insulating package installed.
In order to achieve the best thermal insulation the following comprehensive inslulating package comprise of following membrane lyers:
1. Outer membrane.
2. Air gap.
3. IZOVOL foil insulation layer 50 mm thick (thermal resistance is equivalent to that of a red brick wall 800 mm deep).
4. Air gap.
5. Inner membrane.
6. Aluminum subframe indoor insulation.
Package's Thermal Resistance is 8,1 m2 * K/W which is the same as red brick wall 4,5 m. deep.
The structures may be erected upon:
1. Concrete strip foundation. The minimum height is determined by the depth of permafrost in any particular region, the minimum width - 500 mm.
2. Concrete pillows with embedded parts linked by grillage (for the soils not prone to swelling).
At the upper segment of a structure the membrane can be comprised of light transmitting fabric called "the Lamp". The "Lamp" in the middle of the roof running the entire length of the building will ensure energy savings during daylight hours.
Due to the excellent thermal insulation the heating costs of the building are actually amount solely to heating incoming air needed for venting. Specific volumes are based upon individual use of any given structure.